utils.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #define _XOPEN_SOURCE 600
  20 #define __USE_XOPEN2K
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #ifndef __CHECKER__
  24 #include <sys/ioctl.h>
  25 #include <sys/mount.h>
  26 #endif
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <uuid/uuid.h>
  30 #include <dirent.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <mntent.h>
  34 #include "kerncompat.h"
  35 #include "radix-tree.h"
  36 #include "ctree.h"
  37 #include "disk-io.h"
  38 #include "transaction.h"
  39 #include "crc32c.h"
  40 #include "utils.h"
  41 #include "volumes.h"
  42 #include "ioctl.h"
  43
  44 #ifdef __CHECKER__
  45 #define BLKGETSIZE64 0
  46 static inline int ioctl(int fd, int define, u64 *size) { return 0; }
  47 #endif
  48
  49 static u64 reference_root_table[6] = {
  50         [1] =   BTRFS_ROOT_TREE_OBJECTID,
  51         [2] =   BTRFS_EXTENT_TREE_OBJECTID,
  52         [3] =   BTRFS_CHUNK_TREE_OBJECTID,
  53         [4] =   BTRFS_DEV_TREE_OBJECTID,
  54         [5] =   BTRFS_FS_TREE_OBJECTID,
  55 };
  56
  57 int make_btrfs(int fd, char *device_name,
  58                u64 blocks[6], u64 num_bytes, u32 nodesize,
  59                u32 leafsize, u32 sectorsize, u32 stripesize)
  60 {
  61         struct btrfs_super_block super;
  62         struct extent_buffer *buf;
  63         struct btrfs_root_item root_item;
  64         struct btrfs_disk_key disk_key;
  65         struct btrfs_extent_ref *extent_ref;
  66         struct btrfs_extent_item *extent_item;
  67         struct btrfs_inode_item *inode_item;
  68         struct btrfs_chunk *chunk;
  69         struct btrfs_dev_item *dev_item;
  70         struct btrfs_dev_extent *dev_extent;
  71         u8 *ptr;
  72         int i;
  73         int ret;
  74         u32 itemoff;
  75         u32 nritems = 0;
  76         u64 hash;
  77         u64 first_free;
  78         u64 ref_gen;
  79         u64 ref_root;
  80         u32 array_size;
  81         u32 item_size;
  82
  83         first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
  84         first_free &= ~((u64)sectorsize - 1);
  85
  86         num_bytes = (num_bytes / sectorsize) * sectorsize;
  87         uuid_generate(super.fsid);
  88         btrfs_set_super_bytenr(&super, blocks[0]);
  89         btrfs_set_super_num_devices(&super, 1);
  90         strncpy((char *)&super.magic, BTRFS_MAGIC, sizeof(super.magic));
  91         btrfs_set_super_generation(&super, 1);
  92         btrfs_set_super_root(&super, blocks[1]);
  93         btrfs_set_super_chunk_root(&super, blocks[3]);
  94         btrfs_set_super_total_bytes(&super, num_bytes);
  95         btrfs_set_super_bytes_used(&super, first_free + 5 * leafsize);
  96         btrfs_set_super_root_dir(&super, 0);
  97         btrfs_set_super_sectorsize(&super, sectorsize);
  98         btrfs_set_super_leafsize(&super, leafsize);
  99         btrfs_set_super_nodesize(&super, nodesize);
 100         btrfs_set_super_stripesize(&super, stripesize);
 101         btrfs_set_super_root_level(&super, 0);
 102         btrfs_set_super_chunk_root_level(&super, 0);
 103         btrfs_set_super_sys_array_size(&super, 0);
 104
 105         buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
 106
 107         /* create the tree of root objects */
 108         memset(buf->data, 0, leafsize);
 109         btrfs_set_header_bytenr(buf, blocks[1]);
 110         btrfs_set_header_nritems(buf, 3);
 111         btrfs_set_header_generation(buf, 1);
 112         btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
 113         write_extent_buffer(buf, super.fsid, (unsigned long)
 114                             btrfs_header_fsid(buf), BTRFS_FSID_SIZE);
 115
 116         /* create the items for the root tree */
 117         memset(&root_item, 0, sizeof(root_item));
 118         inode_item = &root_item.inode;
 119         btrfs_set_stack_inode_generation(inode_item, 1);
 120         btrfs_set_stack_inode_size(inode_item, 3);
 121         btrfs_set_stack_inode_nlink(inode_item, 1);
 122         btrfs_set_stack_inode_nblocks(inode_item, 1);
 123         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 124         btrfs_set_root_refs(&root_item, 1);
 125         btrfs_set_root_used(&root_item, leafsize);
 126
 127         memset(&disk_key, 0, sizeof(disk_key));
 128         btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
 129         btrfs_set_disk_key_offset(&disk_key, 0);
 130         nritems = 0;
 131
 132         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
 133         btrfs_set_root_bytenr(&root_item, blocks[2]);
 134         btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
 135         btrfs_set_item_key(buf, &disk_key, nritems);
 136         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 137         btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 138                             sizeof(root_item));
 139         write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
 140                             nritems), sizeof(root_item));
 141         nritems++;
 142
 143         itemoff = itemoff - sizeof(root_item);
 144         btrfs_set_root_bytenr(&root_item, blocks[4]);
 145         btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
 146         btrfs_set_item_key(buf, &disk_key, nritems);
 147         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 148         btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 149                             sizeof(root_item));
 150         write_extent_buffer(buf, &root_item,
 151                             btrfs_item_ptr_offset(buf, nritems),
 152                             sizeof(root_item));
 153         nritems++;
 154
 155         itemoff = itemoff - sizeof(root_item);
 156         btrfs_set_root_bytenr(&root_item, blocks[5]);
 157         btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
 158         btrfs_set_item_key(buf, &disk_key, nritems);
 159         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 160         btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 161                             sizeof(root_item));
 162         write_extent_buffer(buf, &root_item,
 163                             btrfs_item_ptr_offset(buf, nritems),
 164                             sizeof(root_item));
 165         nritems++;
 166
 167
 168         ret = pwrite(fd, buf->data, leafsize, blocks[1]);
 169         BUG_ON(ret != leafsize);
 170
 171         /* create the items for the extent tree */
 172         nritems = 0;
 173         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
 174                   sizeof(struct btrfs_extent_item);
 175         btrfs_set_disk_key_objectid(&disk_key, 0);
 176         btrfs_set_disk_key_offset(&disk_key, first_free);
 177         btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
 178         btrfs_set_item_key(buf, &disk_key, nritems);
 179         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 180         btrfs_set_item_size(buf, btrfs_item_nr(buf,  nritems),
 181                             sizeof(struct btrfs_extent_item));
 182         extent_item = btrfs_item_ptr(buf, nritems, struct btrfs_extent_item);
 183         btrfs_set_extent_refs(buf, extent_item, 1);
 184         nritems++;
 185         for (i = 1; i < 6; i++) {
 186                 BUG_ON(blocks[i] < first_free);
 187                 BUG_ON(blocks[i] < blocks[i - 1]);
 188
 189                 /* create extent item */
 190                 itemoff = itemoff - sizeof(struct btrfs_extent_item);
 191                 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
 192                 btrfs_set_disk_key_offset(&disk_key, leafsize);
 193                 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
 194                 btrfs_set_item_key(buf, &disk_key, nritems);
 195                 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
 196                                       itemoff);
 197                 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 198                                     sizeof(struct btrfs_extent_item));
 199                 extent_item = btrfs_item_ptr(buf, nritems,
 200                                              struct btrfs_extent_item);
 201                 btrfs_set_extent_refs(buf, extent_item, 1);
 202                 nritems++;
 203
 204                 /* create extent ref */
 205                 ref_root = reference_root_table[i];
 206                 if (ref_root == BTRFS_FS_TREE_OBJECTID)
 207                         ref_gen = 1;
 208                 else
 209                         ref_gen = 0;
 210
 211                 hash = btrfs_hash_extent_ref(ref_root, ref_gen, 0, 0);
 212                 itemoff = itemoff - sizeof(struct btrfs_extent_ref);
 213                 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
 214                 btrfs_set_disk_key_offset(&disk_key, hash);
 215                 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_REF_KEY);
 216                 btrfs_set_item_key(buf, &disk_key, nritems);
 217                 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
 218                                       itemoff);
 219                 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 220                                     sizeof(struct btrfs_extent_ref));
 221                 extent_ref = btrfs_item_ptr(buf, nritems,
 222                                              struct btrfs_extent_ref);
 223                 btrfs_set_ref_root(buf, extent_ref, ref_root);
 224                 btrfs_set_ref_generation(buf, extent_ref, ref_gen);
 225                 btrfs_set_ref_objectid(buf, extent_ref, 0);
 226                 btrfs_set_ref_offset(buf, extent_ref, 0);
 227                 nritems++;
 228         }
 229         btrfs_set_header_bytenr(buf, blocks[2]);
 230         btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
 231         btrfs_set_header_nritems(buf, nritems);
 232         ret = pwrite(fd, buf->data, leafsize, blocks[2]);
 233         BUG_ON(ret != leafsize);
 234
 235         /* create the chunk tree */
 236         nritems = 0;
 237         item_size = btrfs_chunk_item_size(1);
 238         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;
 239
 240         /* first we have chunk 0 */
 241         btrfs_set_disk_key_objectid(&disk_key, 0);
 242         btrfs_set_disk_key_offset(&disk_key, BTRFS_MKFS_SYSTEM_GROUP_SIZE);
 243         btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
 244         btrfs_set_item_key(buf, &disk_key, nritems);
 245         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 246         btrfs_set_item_size(buf, btrfs_item_nr(buf,  nritems), item_size);
 247
 248         chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);
 249         btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
 250         btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
 251         btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);
 252         btrfs_set_chunk_io_align(buf, chunk, sectorsize);
 253         btrfs_set_chunk_io_width(buf, chunk, sectorsize);
 254         btrfs_set_chunk_sector_size(buf, chunk, sectorsize);
 255         btrfs_set_chunk_num_stripes(buf, chunk, 1);
 256         btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
 257         btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);
 258
 259         /* copy the key for the chunk to the system array */
 260         ptr = super.sys_chunk_array;
 261         array_size = sizeof(disk_key);
 262
 263         memcpy(ptr, &disk_key, sizeof(disk_key));
 264         ptr += sizeof(disk_key);
 265
 266         /* copy the chunk to the system array */
 267         read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);
 268         array_size += item_size;
 269         ptr += item_size;
 270         btrfs_set_super_sys_array_size(&super, array_size);
 271
 272         /* then device 1 (there is no device 0) */
 273         nritems++;
 274         item_size = sizeof(*dev_item);
 275         itemoff = itemoff - item_size;
 276         btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
 277         btrfs_set_disk_key_offset(&disk_key, 1);
 278         btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
 279         btrfs_set_item_key(buf, &disk_key, nritems);
 280         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 281         btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);
 282
 283         dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);
 284         btrfs_set_device_id(buf, dev_item, 1);
 285         btrfs_set_device_total_bytes(buf, dev_item, num_bytes);
 286         btrfs_set_device_bytes_used(buf, dev_item,
 287                                     BTRFS_MKFS_SYSTEM_GROUP_SIZE);
 288         btrfs_set_device_io_align(buf, dev_item, sectorsize);
 289         btrfs_set_device_io_width(buf, dev_item, sectorsize);
 290         btrfs_set_device_sector_size(buf, dev_item, sectorsize);
 291         btrfs_set_device_type(buf, dev_item, 0);
 292         nritems++;
 293
 294         uuid_generate(super.dev_item.uuid);
 295
 296         write_extent_buffer(buf, super.dev_item.uuid,
 297                             (unsigned long)btrfs_device_uuid(dev_item),
 298                             BTRFS_DEV_UUID_SIZE);
 299         read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,
 300                            sizeof(*dev_item));
 301
 302         btrfs_set_header_bytenr(buf, blocks[3]);
 303         btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
 304         btrfs_set_header_nritems(buf, nritems);
 305         ret = pwrite(fd, buf->data, leafsize, blocks[3]);
 306
 307         /* create the device tree */
 308         nritems = 0;
 309         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
 310                 sizeof(struct btrfs_dev_extent);
 311
 312         btrfs_set_disk_key_objectid(&disk_key, 1);
 313         btrfs_set_disk_key_offset(&disk_key, 0);
 314         btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
 315         btrfs_set_item_key(buf, &disk_key, nritems);
 316         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 317         btrfs_set_item_size(buf, btrfs_item_nr(buf,  nritems),
 318                             sizeof(struct btrfs_dev_extent));
 319         dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);
 320         btrfs_set_dev_extent_owner(buf, dev_extent, 0);
 321         btrfs_set_dev_extent_length(buf, dev_extent,
 322                                     BTRFS_MKFS_SYSTEM_GROUP_SIZE);
 323         nritems++;
 324
 325         btrfs_set_header_bytenr(buf, blocks[4]);
 326         btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
 327         btrfs_set_header_nritems(buf, nritems);
 328         ret = pwrite(fd, buf->data, leafsize, blocks[4]);
 329
 330         /* finally create the FS root */
 331         btrfs_set_header_bytenr(buf, blocks[5]);
 332         btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
 333         btrfs_set_header_nritems(buf, 0);
 334         ret = pwrite(fd, buf->data, leafsize, blocks[5]);
 335         BUG_ON(ret != leafsize);
 336
 337         /* and write out the super block */
 338         BUG_ON(sizeof(super) > sectorsize);
 339         memset(buf->data, 0, sectorsize);
 340         memcpy(buf->data, &super, sizeof(super));
 341         ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
 342         BUG_ON(ret != sectorsize);
 343
 344
 345         free(buf);
 346         return 0;
 347 }
 348
 349 static u64 device_size(int fd, struct stat *st)
 350 {
 351         u64 size;
 352         if (S_ISREG(st->st_mode)) {
 353                 return st->st_size;
 354         }
 355         if (!S_ISBLK(st->st_mode)) {
 356                 return 0;
 357         }
 358         if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
 359                 return size;
 360         }
 361         return 0;
 362 }
 363
 364 static int zero_blocks(int fd, off_t start, size_t len)
 365 {
 366         char *buf = malloc(len);
 367         int ret = 0;
 368         ssize_t written;
 369
 370         if (!buf)
 371                 return -ENOMEM;
 372         memset(buf, 0, len);
 373         written = pwrite(fd, buf, len, start);
 374         if (written != len)
 375                 ret = -EIO;
 376         free(buf);
 377         return ret;
 378 }
 379
 380 static int zero_dev_start(int fd)
 381 {
 382         off_t start = 0;
 383         size_t len = 2 * 1024 * 1024;
 384
 385 #ifdef __sparc__
 386         /* don't overwrite the disk labels on sparc */
 387         start = 1024;
 388         len -= 1024;
 389 #endif
 390         return zero_blocks(fd, start, len);
 391 }
 392
 393 static int zero_dev_end(int fd, u64 dev_size)
 394 {
 395         size_t len = 2 * 1024 * 1024;
 396         off_t start = dev_size - len;
 397
 398         return zero_blocks(fd, start, len);
 399 }
 400
 401 int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
 402                       struct btrfs_root *root, int fd, u64 block_count,
 403                       u32 io_width, u32 io_align, u32 sectorsize)
 404 {
 405         struct btrfs_super_block *disk_super;
 406         struct btrfs_super_block *super = &root->fs_info->super_copy;
 407         struct btrfs_device *device;
 408         struct btrfs_dev_item *dev_item;
 409         char *buf;
 410         u64 total_bytes;
 411         u64 num_devs;
 412         int ret;
 413
 414         device = kmalloc(sizeof(*device), GFP_NOFS);
 415         if (!device)
 416                 return -ENOMEM;
 417         buf = kmalloc(sectorsize, GFP_NOFS);
 418         if (!buf) {
 419                 kfree(device);
 420                 return -ENOMEM;
 421         }
 422         BUG_ON(sizeof(*disk_super) > sectorsize);
 423         memset(buf, 0, sectorsize);
 424
 425         disk_super = (struct btrfs_super_block *)buf;
 426         dev_item = &disk_super->dev_item;
 427
 428         uuid_generate(device->uuid);
 429         device->devid = 0;
 430         device->type = 0;
 431         device->io_width = io_width;
 432         device->io_align = io_align;
 433         device->sector_size = sectorsize;
 434         device->fd = fd;
 435         device->total_bytes = block_count;
 436         device->bytes_used = 0;
 437         device->total_ios = 0;
 438         device->dev_root = root->fs_info->dev_root;
 439
 440         ret = btrfs_add_device(trans, root, device);
 441         BUG_ON(ret);
 442
 443         total_bytes = btrfs_super_total_bytes(super) + block_count;
 444         btrfs_set_super_total_bytes(super, total_bytes);
 445
 446         num_devs = btrfs_super_num_devices(super) + 1;
 447         btrfs_set_super_num_devices(super, num_devs);
 448
 449         memcpy(disk_super, super, sizeof(*disk_super));
 450
 451         printf("adding device id %llu\n", (unsigned long long)device->devid);
 452         btrfs_set_stack_device_id(dev_item, device->devid);
 453         btrfs_set_stack_device_type(dev_item, device->type);
 454         btrfs_set_stack_device_io_align(dev_item, device->io_align);
 455         btrfs_set_stack_device_io_width(dev_item, device->io_width);
 456         btrfs_set_stack_device_sector_size(dev_item, device->sector_size);
 457         btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);
 458         btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);
 459         memcpy(&dev_item->uuid, device->uuid, BTRFS_DEV_UUID_SIZE);
 460
 461         ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
 462         BUG_ON(ret != sectorsize);
 463
 464         kfree(buf);
 465         list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
 466         return 0;
 467 }
 468
 469 int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret)
 470 {
 471         u64 block_count;
 472         struct stat st;
 473         int ret;
 474
 475         ret = fstat(fd, &st);
 476         if (ret < 0) {
 477                 fprintf(stderr, "unable to stat %s\n", file);
 478                 exit(1);
 479         }
 480
 481         block_count = device_size(fd, &st);
 482         if (block_count == 0) {
 483                 fprintf(stderr, "unable to find %s size\n", file);
 484                 exit(1);
 485         }
 486         zero_end = 1;
 487
 488         if (block_count < 256 * 1024 * 1024) {
 489                 fprintf(stderr, "device %s is too small\n", file);
 490                 exit(1);
 491         }
 492         ret = zero_dev_start(fd);
 493         if (ret) {
 494                 fprintf(stderr, "failed to zero device start %d\n", ret);
 495                 exit(1);
 496         }
 497
 498         if (zero_end) {
 499                 ret = zero_dev_end(fd, block_count);
 500                 if (ret) {
 501                         fprintf(stderr, "failed to zero device end %d\n", ret);
 502                         exit(1);
 503                 }
 504         }
 505         *block_count_ret = block_count;
 506         return 0;
 507 }
 508
 509 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
 510                         struct btrfs_root *root, u64 objectid)
 511 {
 512         int ret;
 513         struct btrfs_inode_item inode_item;
 514
 515         memset(&inode_item, 0, sizeof(inode_item));
 516         btrfs_set_stack_inode_generation(&inode_item, trans->transid);
 517         btrfs_set_stack_inode_size(&inode_item, 0);
 518         btrfs_set_stack_inode_nlink(&inode_item, 1);
 519         btrfs_set_stack_inode_nblocks(&inode_item, 1);
 520         btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0555);
 521
 522         if (root->fs_info->tree_root == root)
 523                 btrfs_set_super_root_dir(&root->fs_info->super_copy, objectid);
 524
 525         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
 526         if (ret)
 527                 goto error;
 528
 529         ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid);
 530         if (ret)
 531                 goto error;
 532
 533         btrfs_set_root_dirid(&root->root_item, objectid);
 534         ret = 0;
 535 error:
 536         return ret;
 537 }
 538
 539 /*
 540  * returns 1 if the device was mounted, < 0 on error or 0 if everything
 541  * is safe to continue.  TODO, this should also scan multi-device filesystems
 542  */
 543 int check_mounted(char *file)
 544 {
 545         struct mntent *mnt;
 546         struct stat st_buf;
 547         dev_t file_dev = 0;
 548         dev_t file_rdev = 0;
 549         ino_t file_ino = 0;
 550         FILE *f;
 551         int ret = 0;
 552
 553         if ((f = setmntent ("/proc/mounts", "r")) == NULL)
 554                 return -errno;
 555
 556         if (stat(file, &st_buf) < 0) {
 557                 return -errno;
 558         } else {
 559                 if (S_ISBLK(st_buf.st_mode)) {
 560                         file_rdev = st_buf.st_rdev;
 561                 } else {
 562                         file_dev = st_buf.st_dev;
 563                         file_ino = st_buf.st_ino;
 564                 }
 565         }
 566
 567         while ((mnt = getmntent (f)) != NULL) {
 568                 if (strcmp(file, mnt->mnt_fsname) == 0)
 569                         break;
 570
 571                 if (stat(mnt->mnt_fsname, &st_buf) == 0) {
 572                         if (S_ISBLK(st_buf.st_mode)) {
 573                                 if (file_rdev && (file_rdev == st_buf.st_rdev))
 574                                         break;
 575                         } else if (file_dev && ((file_dev == st_buf.st_dev) &&
 576                                                 (file_ino == st_buf.st_ino))) {
 577                                         break;
 578                         }
 579                 }
 580         }
 581
 582         if (mnt) {
 583                 /* found an entry in mnt table */
 584                 ret = 1;
 585         }
 586
 587         endmntent (f);
 588         return ret;
 589 }
 590
 591 struct pending_dir {
 592         struct list_head list;
 593         char name[256];
 594 };
 595
 596 int btrfs_register_one_device(char *fname)
 597 {
 598         struct btrfs_ioctl_vol_args args;
 599         int fd;
 600         int ret;
 601
 602         fd = open("/dev/btrfs-control", O_RDONLY);
 603         if (fd < 0)
 604                 return -EINVAL;
 605         strcpy(args.name, fname);
 606         ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
 607         close(fd);
 608         return ret;
 609 }
 610
 611 int btrfs_scan_one_dir(char *dirname, int run_ioctl)
 612 {
 613         DIR *dirp;
 614         struct dirent *dirent;
 615         struct pending_dir *pending;
 616         struct stat st;
 617         int ret;
 618         int fd;
 619         int dirname_len;
 620         int pathlen;
 621         char *fullpath;
 622         struct list_head pending_list;
 623         struct btrfs_fs_devices *tmp_devices;
 624         u64 num_devices;
 625
 626         INIT_LIST_HEAD(&pending_list);
 627
 628         pending = malloc(sizeof(*pending));
 629         if (!pending)
 630                 return -ENOMEM;
 631         strcpy(pending->name, dirname);
 632
 633 again:
 634         dirname_len = strlen(pending->name);
 635         pathlen = 1024;
 636         fullpath = malloc(pathlen);
 637         dirname = pending->name;
 638
 639         if (!fullpath) {
 640                 ret = -ENOMEM;
 641                 goto fail;
 642         }
 643         dirp = opendir(dirname);
 644         if (!dirp) {
 645                 fprintf(stderr, "Unable to open /sys/block for scanning\n");
 646                 return -ENOENT;
 647         }
 648         while(1) {
 649                 dirent = readdir(dirp);
 650                 if (!dirent)
 651                         break;
 652                 if (dirent->d_name[0] == '.')
 653                         continue;
 654                 if (dirname_len + strlen(dirent->d_name) + 2 > pathlen) {
 655                         ret = -EFAULT;
 656                         goto fail;
 657                 }
 658                 snprintf(fullpath, pathlen, "%s/%s", dirname, dirent->d_name);
 659                 ret = lstat(fullpath, &st);
 660                 if (ret < 0) {
 661                         fprintf(stderr, "failed to stat %s\n", fullpath);
 662                         continue;
 663                 }
 664                 if (S_ISLNK(st.st_mode))
 665                         continue;
 666                 if (S_ISDIR(st.st_mode)) {
 667                         struct pending_dir *next = malloc(sizeof(*next));
 668                         if (!next) {
 669                                 ret = -ENOMEM;
 670                                 goto fail;
 671                         }
 672                         strcpy(next->name, fullpath);
 673                         list_add_tail(&next->list, &pending_list);
 674                 }
 675                 if (!S_ISBLK(st.st_mode)) {
 676                         continue;
 677                 }
 678                 fd = open(fullpath, O_RDONLY);
 679                 if (fd < 0) {
 680                         fprintf(stderr, "failed to read %s\n", fullpath);
 681                         continue;
 682                 }
 683                 ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices,
 684                                             &num_devices,
 685                                             BTRFS_SUPER_INFO_OFFSET);
 686                 if (ret == 0 && run_ioctl > 0) {
 687                         btrfs_register_one_device(fullpath);
 688                 }
 689                 close(fd);
 690         }
 691         if (!list_empty(&pending_list)) {
 692                 free(pending);
 693                 pending = list_entry(pending_list.next, struct pending_dir,
 694                                      list);
 695                 list_del(&pending->list);
 696                 closedir(dirp);
 697                 goto again;
 698         }
 699         ret = 0;
 700 fail:
 701         free(pending);
 702         closedir(dirp);
 703         return ret;
 704 }
 705
 706 int btrfs_scan_for_fsid(struct btrfs_fs_devices *fs_devices, u64 total_devs,
 707                         int run_ioctls)
 708 {
 709         return btrfs_scan_one_dir("/dev", run_ioctls);
 710 }